mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-11-20 08:38:24 +08:00
Btrfs: don't preallocate metadata blocks during btrfs_search_slot
In order to avoid doing expensive extent management with tree locks held, btrfs_search_slot will preallocate tree blocks for use by COW without any tree locks held. A later commit moves all of the extent allocation work for COW into a delayed update mechanism, and this preallocation will no longer be required. Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
parent
8e0ee43bc2
commit
9fa8cfe706
100
fs/btrfs/ctree.c
100
fs/btrfs/ctree.c
@ -254,18 +254,13 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
|
||||
* empty_size -- a hint that you plan on doing more cow. This is the size in
|
||||
* bytes the allocator should try to find free next to the block it returns.
|
||||
* This is just a hint and may be ignored by the allocator.
|
||||
*
|
||||
* prealloc_dest -- if you have already reserved a destination for the cow,
|
||||
* this uses that block instead of allocating a new one.
|
||||
* btrfs_alloc_reserved_extent is used to finish the allocation.
|
||||
*/
|
||||
static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
struct btrfs_root *root,
|
||||
struct extent_buffer *buf,
|
||||
struct extent_buffer *parent, int parent_slot,
|
||||
struct extent_buffer **cow_ret,
|
||||
u64 search_start, u64 empty_size,
|
||||
u64 prealloc_dest)
|
||||
u64 search_start, u64 empty_size)
|
||||
{
|
||||
u64 parent_start;
|
||||
struct extent_buffer *cow;
|
||||
@ -291,26 +286,10 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
level = btrfs_header_level(buf);
|
||||
nritems = btrfs_header_nritems(buf);
|
||||
|
||||
if (prealloc_dest) {
|
||||
struct btrfs_key ins;
|
||||
|
||||
ins.objectid = prealloc_dest;
|
||||
ins.offset = buf->len;
|
||||
ins.type = BTRFS_EXTENT_ITEM_KEY;
|
||||
|
||||
ret = btrfs_alloc_reserved_extent(trans, root, parent_start,
|
||||
root->root_key.objectid,
|
||||
trans->transid, level, &ins);
|
||||
BUG_ON(ret);
|
||||
cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
|
||||
buf->len, level);
|
||||
} else {
|
||||
cow = btrfs_alloc_free_block(trans, root, buf->len,
|
||||
parent_start,
|
||||
root->root_key.objectid,
|
||||
trans->transid, level,
|
||||
search_start, empty_size);
|
||||
}
|
||||
cow = btrfs_alloc_free_block(trans, root, buf->len,
|
||||
parent_start, root->root_key.objectid,
|
||||
trans->transid, level,
|
||||
search_start, empty_size);
|
||||
if (IS_ERR(cow))
|
||||
return PTR_ERR(cow);
|
||||
|
||||
@ -413,7 +392,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
struct btrfs_root *root, struct extent_buffer *buf,
|
||||
struct extent_buffer *parent, int parent_slot,
|
||||
struct extent_buffer **cow_ret, u64 prealloc_dest)
|
||||
struct extent_buffer **cow_ret)
|
||||
{
|
||||
u64 search_start;
|
||||
int ret;
|
||||
@ -436,7 +415,6 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
btrfs_header_owner(buf) == root->root_key.objectid &&
|
||||
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
|
||||
*cow_ret = buf;
|
||||
WARN_ON(prealloc_dest);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -447,8 +425,7 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
btrfs_set_lock_blocking(buf);
|
||||
|
||||
ret = __btrfs_cow_block(trans, root, buf, parent,
|
||||
parent_slot, cow_ret, search_start, 0,
|
||||
prealloc_dest);
|
||||
parent_slot, cow_ret, search_start, 0);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -617,7 +594,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
|
||||
err = __btrfs_cow_block(trans, root, cur, parent, i,
|
||||
&cur, search_start,
|
||||
min(16 * blocksize,
|
||||
(end_slot - i) * blocksize), 0);
|
||||
(end_slot - i) * blocksize));
|
||||
if (err) {
|
||||
btrfs_tree_unlock(cur);
|
||||
free_extent_buffer(cur);
|
||||
@ -937,7 +914,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
|
||||
BUG_ON(!child);
|
||||
btrfs_tree_lock(child);
|
||||
btrfs_set_lock_blocking(child);
|
||||
ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
|
||||
ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
|
||||
BUG_ON(ret);
|
||||
|
||||
spin_lock(&root->node_lock);
|
||||
@ -979,7 +956,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
|
||||
btrfs_tree_lock(left);
|
||||
btrfs_set_lock_blocking(left);
|
||||
wret = btrfs_cow_block(trans, root, left,
|
||||
parent, pslot - 1, &left, 0);
|
||||
parent, pslot - 1, &left);
|
||||
if (wret) {
|
||||
ret = wret;
|
||||
goto enospc;
|
||||
@ -990,7 +967,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
|
||||
btrfs_tree_lock(right);
|
||||
btrfs_set_lock_blocking(right);
|
||||
wret = btrfs_cow_block(trans, root, right,
|
||||
parent, pslot + 1, &right, 0);
|
||||
parent, pslot + 1, &right);
|
||||
if (wret) {
|
||||
ret = wret;
|
||||
goto enospc;
|
||||
@ -1171,7 +1148,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
|
||||
wret = 1;
|
||||
} else {
|
||||
ret = btrfs_cow_block(trans, root, left, parent,
|
||||
pslot - 1, &left, 0);
|
||||
pslot - 1, &left);
|
||||
if (ret)
|
||||
wret = 1;
|
||||
else {
|
||||
@ -1222,7 +1199,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
|
||||
} else {
|
||||
ret = btrfs_cow_block(trans, root, right,
|
||||
parent, pslot + 1,
|
||||
&right, 0);
|
||||
&right);
|
||||
if (ret)
|
||||
wret = 1;
|
||||
else {
|
||||
@ -1492,7 +1469,6 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||
u8 lowest_level = 0;
|
||||
u64 blocknr;
|
||||
u64 gen;
|
||||
struct btrfs_key prealloc_block;
|
||||
|
||||
lowest_level = p->lowest_level;
|
||||
WARN_ON(lowest_level && ins_len > 0);
|
||||
@ -1501,8 +1477,6 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||
if (ins_len < 0)
|
||||
lowest_unlock = 2;
|
||||
|
||||
prealloc_block.objectid = 0;
|
||||
|
||||
again:
|
||||
if (p->skip_locking)
|
||||
b = btrfs_root_node(root);
|
||||
@ -1529,44 +1503,11 @@ again:
|
||||
!btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
|
||||
goto cow_done;
|
||||
}
|
||||
|
||||
/* ok, we have to cow, is our old prealloc the right
|
||||
* size?
|
||||
*/
|
||||
if (prealloc_block.objectid &&
|
||||
prealloc_block.offset != b->len) {
|
||||
btrfs_release_path(root, p);
|
||||
btrfs_free_reserved_extent(root,
|
||||
prealloc_block.objectid,
|
||||
prealloc_block.offset);
|
||||
prealloc_block.objectid = 0;
|
||||
goto again;
|
||||
}
|
||||
|
||||
/*
|
||||
* for higher level blocks, try not to allocate blocks
|
||||
* with the block and the parent locks held.
|
||||
*/
|
||||
if (level > 0 && !prealloc_block.objectid) {
|
||||
u32 size = b->len;
|
||||
u64 hint = b->start;
|
||||
|
||||
btrfs_release_path(root, p);
|
||||
ret = btrfs_reserve_extent(trans, root,
|
||||
size, size, 0,
|
||||
hint, (u64)-1,
|
||||
&prealloc_block, 0);
|
||||
BUG_ON(ret);
|
||||
goto again;
|
||||
}
|
||||
|
||||
btrfs_set_path_blocking(p);
|
||||
|
||||
wret = btrfs_cow_block(trans, root, b,
|
||||
p->nodes[level + 1],
|
||||
p->slots[level + 1],
|
||||
&b, prealloc_block.objectid);
|
||||
prealloc_block.objectid = 0;
|
||||
p->slots[level + 1], &b);
|
||||
if (wret) {
|
||||
free_extent_buffer(b);
|
||||
ret = wret;
|
||||
@ -1743,11 +1684,6 @@ done:
|
||||
* from here on, so for now just mark it as blocking
|
||||
*/
|
||||
btrfs_set_path_blocking(p);
|
||||
if (prealloc_block.objectid) {
|
||||
btrfs_free_reserved_extent(root,
|
||||
prealloc_block.objectid,
|
||||
prealloc_block.offset);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -1768,7 +1704,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
|
||||
int ret;
|
||||
|
||||
eb = btrfs_lock_root_node(root);
|
||||
ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0);
|
||||
ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb);
|
||||
BUG_ON(ret);
|
||||
|
||||
btrfs_set_lock_blocking(eb);
|
||||
@ -1826,7 +1762,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
|
||||
}
|
||||
|
||||
ret = btrfs_cow_block(trans, root, eb, parent, slot,
|
||||
&eb, 0);
|
||||
&eb);
|
||||
BUG_ON(ret);
|
||||
|
||||
if (root->root_key.objectid ==
|
||||
@ -2377,7 +2313,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||
|
||||
/* cow and double check */
|
||||
ret = btrfs_cow_block(trans, root, right, upper,
|
||||
slot + 1, &right, 0);
|
||||
slot + 1, &right);
|
||||
if (ret)
|
||||
goto out_unlock;
|
||||
|
||||
@ -2576,7 +2512,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||
|
||||
/* cow and double check */
|
||||
ret = btrfs_cow_block(trans, root, left,
|
||||
path->nodes[1], slot - 1, &left, 0);
|
||||
path->nodes[1], slot - 1, &left);
|
||||
if (ret) {
|
||||
/* we hit -ENOSPC, but it isn't fatal here */
|
||||
ret = 1;
|
||||
|
||||
@ -1838,7 +1838,7 @@ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
|
||||
int btrfs_cow_block(struct btrfs_trans_handle *trans,
|
||||
struct btrfs_root *root, struct extent_buffer *buf,
|
||||
struct extent_buffer *parent, int parent_slot,
|
||||
struct extent_buffer **cow_ret, u64 prealloc_dest);
|
||||
struct extent_buffer **cow_ret);
|
||||
int btrfs_copy_root(struct btrfs_trans_handle *trans,
|
||||
struct btrfs_root *root,
|
||||
struct extent_buffer *buf,
|
||||
|
||||
@ -463,7 +463,7 @@ int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
|
||||
btrfs_extent_post_op(trans, fs_info->tree_root);
|
||||
|
||||
eb = btrfs_lock_root_node(fs_info->tree_root);
|
||||
btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb, 0);
|
||||
btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
|
||||
btrfs_tree_unlock(eb);
|
||||
free_extent_buffer(eb);
|
||||
|
||||
@ -766,7 +766,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
|
||||
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
|
||||
|
||||
old = btrfs_lock_root_node(root);
|
||||
btrfs_cow_block(trans, root, old, NULL, 0, &old, 0);
|
||||
btrfs_cow_block(trans, root, old, NULL, 0, &old);
|
||||
|
||||
btrfs_copy_root(trans, root, old, &tmp, objectid);
|
||||
btrfs_tree_unlock(old);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user